Second order quantum phase transition of a homogeneous Bose gas with attractive interactions

TL;DR

This paper investigates a second-order quantum phase transition in a homogeneous Bose gas with attractive interactions, analyzing quantum fluctuations near the critical point using advanced theoretical methods.

Contribution

It demonstrates the occurrence of a second-order quantum phase transition at a critical interaction strength and introduces a continuous description to analyze quantum fluctuations beyond mean field theory.

Findings

Identification of a second-order quantum phase transition

Analysis of quantum fluctuations near the critical point

Use of Bogoliubov theory and continuous description methods

Abstract

We consider a homogeneous Bose gas of particles with an attractive interaction. Mean field theory predicts for this system a spontaneous symmetry breaking at a certain value of the interaction strength. We show that at this point a second-order quantum phase transition occurs. We investigate the system in the vicinity of the critical point using Bogoliubov theory and a continuous description, that allows us to analyze {\it quantum fluctuations} in the system even when the Bogoliubov approach breaks down.